A 17-year-old boy who was stabbed to death in Birmingham city centre has been named as Muhammad Hassam Ali.
Police said the victim, who was discovered with serious knife wounds by police in Victoria Square at about 3.30pm on Saturday, appeared to have been killed in a case of mistaken identity.
Detectives from West Midlands Police are hunting for Muhammad's killer as his family released a picture of him.
The force said the stabbing is not believed to be gang-related but have not yet found a motive or made any arrests.
Detective Inspector Michelle Thurgood said: "This is a tragic case of a young man being killed in what appears to be a case of mistaken identity.
"We are still trying to establish the motive and are keen to speak to anyone who was in the area just before 3.30pm yesterday.
"We are especially looking for any photos or video footage from the surrounding area which may help us identify those responsible.
"If you were walking through the area at the time, or a visitor who may have been taking pictures by The River statue near the Council House, we would like to hear from you as you may have vital information or evidence."
The cordon in the square, which is home to Birmingham's city council building, has since been lifted, but there will be a heightened police presence in the area, the force said.
Officers are reviewing CCTV footage and have set up a major incident public portal for people to submit any photos or videos of the incident.